/* Copyright (C) 2000 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include "mysys_priv.h"
#include <m_string.h>

static char *find_file_in_path(char *to, const char *name);

/* Finds where program can find it's files.
   pre_pathname is found by first locking at progname (argv[0]).
   if progname contains path the path is returned.
   else if progname is found in path, return it
   else if progname is given and POSIX environment variable "_" is set
   then path is taken from "_".
   If filename doesn't contain a path append MY_BASEDIR_VERSION or
   MY_BASEDIR if defined, else append "/my/running".
   own_path_name_part is concatinated to result.
   my_path puts result in to and returns to */

my_string my_path(my_string to, const char *progname, const char *own_pathname_part)
{
  my_string start, end, prog;
  DBUG_ENTER("my_path");

  start = to; /* Return this */
  if (progname && (dirname_part(to, progname) || find_file_in_path(to, progname) ||
                   ((prog = getenv("_")) != 0 && dirname_part(to, prog))))
  {
    VOID(intern_filename(to, to));
    if (!test_if_hard_path(to))
    {
      if (!my_getwd(curr_dir, FN_REFLEN, MYF(0)))
        bchange(to, 0, curr_dir, (uint)strlen(curr_dir), (uint)strlen(to) + 1);
    }
  }
  else
  {
    if ((end = getenv("MY_BASEDIR_VERSION")) == 0 && (end = getenv("MY_BASEDIR")) == 0)
    {
#ifdef DEFAULT_BASEDIR
      end = (char *)DEFAULT_BASEDIR;
#else
      end = (char *)"/my/";
#endif
    }
    VOID(intern_filename(to, end));
    to = strend(to);
    if (to != start && to[-1] != FN_LIBCHAR)
      *to++ = FN_LIBCHAR;
    VOID(strmov(to, own_pathname_part));
  }
  DBUG_PRINT("exit", ("to: '%s'", start));
  DBUG_RETURN(start);
} /* my_path */

/* test if file without filename is found in path */
/* Returns to if found and to has dirpart if found, else NullS */

#if defined(MSDOS) || defined(__WIN__) || defined(__EMX__) || defined(OS2)
#define F_OK 0
#define PATH_SEP ';'
#define PROGRAM_EXTENSION ".exe"
#elif defined(__NETWARE__)
#define PATH_SEP ';'
#define PROGRAM_EXTENSION ".nlm"
#else
#define PATH_SEP ':'
#endif

static char *find_file_in_path(char *to, const char *name)
{
  char *path, *pos, dir[2];
  const char *ext = "";

  if (!(path = getenv("PATH")))
    return NullS;
  dir[0] = FN_LIBCHAR;
  dir[1] = 0;
#ifdef PROGRAM_EXTENSION
  if (!fn_ext(name)[0])
    ext = PROGRAM_EXTENSION;
#endif

  for (pos = path; (pos = strchr(pos, PATH_SEP)); path = ++pos)
  {
    if (path != pos)
    {
      strxmov(strnmov(to, path, (uint)(pos - path)), dir, name, ext, NullS);
      if (!access(to, F_OK))
      {
        to[(uint)(pos - path) + 1] = 0; /* Return path only */
        return to;
      }
    }
  }
#ifdef __WIN__
  to[0] = FN_CURLIB;
  strxmov(to + 1, dir, name, ext, NullS);
  if (!access(to, F_OK)) /* Test in current dir */
  {
    to[2] = 0; /* Leave ".\" */
    return to;
  }
#endif
  return NullS; /* File not found */
}
